Use of imaging sensors in vehicle imaging systems is common and known. Examples of such known systems are described in U.S. Pat. Nos. 5,949,331; 5,670,935 and/or 5,550,677, which are hereby incorporated herein by reference in their entireties.
In some systems, when attaching a trailer to the vehicle, the driver has to enter its properties to put the trailer driving aid system into a position to properly calculate the driving aids overlays, when backing up with a trailer attached. Some more advanced systems are able to detect the trailer length and the distance of the trailer's axle to the hatch by watching the trailer's turning behavior when the vehicle and trailer are in motion using visual data processing such as described in U.S. Publication No. US-2014-0160276, which is hereby incorporated herein by reference in its entirety.
Wireless camera data transmission is known, especially Bluetooth® and WLAN. To attach wireless cameras onto vehicles or trailers is also known. Analog image transmission (such as NTSC) to an aftermarket display device installed in the vehicle cabin is common use. In U.S. Publication No. US-2014-0340510, which is hereby incorporated herein by reference in its entirety, the integration of a trailer attached (possibly wireless) camera to an OEM vehicle (possibly top view) vision system is described including the data transmission architecture and the visual human interface. A towing vehicle based trailer stability control is well described in U.S. Publication No. US-2014-0340510.
From German DE 102009057996 (Daimler 2009), it is known how to calibrate a trailer rear-mounted camera relative to a trailing vehicle by visual motion flow analysis via difference image data processing, resulting in a corresponding set of translation and rotation parameters.
In WO 2015/001066, a vehicle trailer back up control system with trailer cameras is disclosed that is able to determine a target route (path plan) with route corridor. Also suggested is 3D representation of the scene. It lacks on describing the according vision processing and camera calibration to do so.